Rotor blades, as are used especially in gas turbines, are exposed to extreme conditions during operation, which is accompanied by a high degree of wear which is caused particularly by oxidation. Accordingly, it is necessary to regularly exchange worn rotor blades in the course of a gas turbine service for new or reconditioned rotor blades. The rotor blades which are to be newly fitted have to be individually adapted to the existing gas turbine at each construction site. In this case, the length of the rotor blade at the feathered edge is reduced in order to establish the distance between the feathered edge of the rotor blade and the gas turbine casing in such a way that during operation of the gas turbine a gap which is as small as possible is established in order to minimize undesirable gas losses.
When shortening the feathered edges of rotor blades grinding machines are normally used. These as a rule comprise a stationary grinding unit with a driven grinding tool, a workpiece mounting device, which is adapted for the mounting of a rotor blade to be ground, and a workpiece drive unit which is designed to move the workpiece mounting device, together with a rotor blade mounted thereon, relative to the grinding tool for the purpose of metal-removing machining of the feathered edge. The workpiece drive unit and the associated controlling of such grinding machines are designed in such a way that they enable a circular interpolation which is required in order to be able to produce the complex geometry of the feathered edge in the form of a tapered section.